Test 4. Chapter 16 Flashcards
what are the 4 general types of cell communication?
contact dependent
paracrine
synaptic
endocrine
the _________ bind to the receptor protein
signaling molecule
The ________ activates intracellular signalling proteins that intiate a ___________–
receptor
signaling cascade
The signaling cascade influences a ___________, altering this target protein and thus altering the behavior of thecell
target protein
_________________ extracellular signal molecule (hormone) that binds to and activates receptor
first messengers
_______________: small molecules that produce in large numbers as a consequence of receptor activation
secondary messengers
_________________: pass the signal on to the next intracellular signaling protein
relay proteins
_____________: link one signaling protein to another, but do not convey the signal themselves. Critcal for the formation of signaling complexes
adapter proteins
_____________: proteins that bind multiple signaling proteins together in a functional complex and often hold them in a specific location
scaffold proteins
_______________: amplify the signal, often by generating second messengers (ion channels and enzymes)
amplifier proteins
______________: locate signaling proteins in a precise location in the cell by tethering them to the membrane or cytoskeleton
anchoring protein
_____________: these are activated at the cell surface by receptors and translocate into the nucleus to regulate gene expression
gene regulatory proteins
what are some common secondary messengers?
cAMP, cGMP, calcium ion, IP3, DAG
Name two types of molecular switches? (to turn on)
signaling by phosphorlation
signaling by GTP binding
Cells often require multiple signal proteins coincidentally to trigger a response. Often,
multiple signals require ______________- which require more than one input signal to
generate an output signal that propagates a downstream signaling cascade.
integrator proteins
G- protein coupled receptors (GPCR) change conformation in response to _______ binding and activated __________–
ligand binding
activated G proteins
in heterotrimeric G protein pathways what are involved?
stimulus/ligand
receptor
g protein
effector
G protein coupled receptors (GPCR) represent _____________ of the current drug target
50-60
inactivated heterotrimeric G protein is bound to __________-
GDP
G- protein mediated activation of ____________ by hormone binding leads to creation of CAMP
adenylate cyclase
most effects of cAMP are mediated by protein….________
protein kinase A (PKA)
Gαq activates phospholipase C, which cleaves the membrane lipid phosphatidylinositol bisphosphate into two second messengers:___________________
inositol 1, 4, 5-trisphosphate (IP3)
diacylglycerol (DAG
What enzyme is used in the reaction where Pip3 makes DAG?
phospholipase C
in phosphoinositide cascade how messengers are required for activation of PKC?
2 messengers
how does GPCR signaling specificity occur?
multiple physiological response
Signalling specificity is achieved by scaffolding in yeast
Scaffolding of _______________is also seen in mammalian cells
MAPK cascade
G proteins spontaneously reset themselves through _________
GTP hydrolysis
Know dissociation
???????
describe guanine analogs and their roles?
N-methylated analogs of guanine
Mimic GTP, bind and stimulate G-proteins
“natural” stimulants
Some receptors dimerize in response to lingand binding and recruit ______________-
tyrosine kinases
each JAK phosphorylates its partner on a typrosine reside, activating the two ___________
kinases
what intially triggers change in gene expression?
ras activation
GTP hydrolysis
MAP kinase phosphorylation
growth factor-receptor binding
Ras belongs to another class of signaling _________
g protein
Why care about ras?
ras is most common onogene in human cancer
The Ras pathway provides a focus on the origins of cancer at the molecular level.
Ras is a key cellular protein for cell growth, differentiation and survival.
the polypeptide hormone __________ is secreted when the blood is rich in glucose. It is the biochemical signal for fed state
insulin
The insulin receptor is a dimer that closes around a bound insulin molecule.
The insulin receptor is a ___________-
Receptor dimers form a insulin binding, leading to _____________ and activation of the kinase domains
tyrosine kinase
cross- phosphorylation
the activated insulin receptor kinase intiates a ___________—
kinase cascade
what is the action of lipid kinase in insulin signaling… give an example
phosphatidylinositide 3 kinase is used to phophoralate Pip2 to Pip3
how does the body inactivate the insulin cascade?
Protein phosphatases remove phosphates from the activated proteins in the insulin signal transduction pathway, terminating the insulin signal.
Lipid phosphatases contribute to signal termination by converting PIP3 into PIP2.
